K2 upgrade mods tactical planning [was:Re: Return of the prodigal daughter]

[Margaret Leber]

I hope Don doesn't mind me bringing part of this private correspondance
back onto the reflector; I'm interested in hearing some discussion on my
own somewhat unique situation.

W3FPR - Don Wilhelm wrote:

> ...they pay me for NOT working - it is called
> retirement, and I'm busier than I ever was when I was working.

I'd be pleased to call this retirement, and I'm quite sufficiently busy,
between keeping up with tech stuff, job hunting, running our household,
and keeping up with ham activities (I edit the Phil-Mont Mobile Radio
Club monthly newsletter, "The Blurb", see http://www.phil-mont.org )

I just don't have that "getting paid for it" thing worked out, and I've
still got one more daughter to put through college.

> You may want to consider a few of the no cost (or low cost) upgrades while
> you are working on that K2 - a couple that come to mind are the AF Gain mod...

Hmmm. That one sure is a no-brainer. When I first got my kit back in
2000, that issue was just surfacing on the reflector; some people were
trying all kinds of component cleaners, etc.

> and the 2nd crystal filter flattening mod - the AF Gain mod takes only wire
> and the 2nd crystal mod takes only a transistor, a cap and a resistor.  I
> know there are others, but I just don't recall them at the moment.  Take a
> look at the K2 A to B upgrade instructions and see what you can do with the
> parts you may have on hand.  

Poop. I thought I knew exactly what I was gonna do, now I've got to make
*decisions* again. ;-)  Let's see...

XFILMDKT (the flattening mod) is only $10; I'm not *that* poor.

> If you can spare $15, I would recommend you buy
> a new set of crystals (a set of 14 for both the base K2 and the KSB2) rather
> than using the ones in your kit - the crystal specs were improved and result
> in a much better filter.  

That would be K2KSB2XTLS? I think I can squeeze that much out too.

So now I should consider the Temperature Compensated PLL Reference
($20)...which requires BFOMDKT ($10), and calls for FWK2MCIO for full
benefit.

So far we're up to $50 total...($51 when I add the speaker cloth. :-) )

I guess the real cost item among all the upgrades is FWK2MCIO.
Ironically, one of the first things I want to do when the kit is done
(and I have a job again) is to add a KIO2...especially since I have a
rig-control software project of my own. (see:

http://jhamtune.netfirms.com/ and http://jhamtune.dev.java.net/

And if I read the Elecraft site correctly, a KIO2 includes the firmware
upgrade when ordered for an earlyish S/N K2 like mine.

(Naturally, once I'm working enough to pay for the KIO2, I probably
won't have as much time to build it, or write a K2 jHamTune driver. :-) )

So I think I'm going to rationalize deferring the firmware upgrade for
now...even though it gripes me to be nickle-and-dimeing a project this
way.

But since the cost is nearly equal, I wonder if it would make sense to
simply order the K2BCOMPKT instead of XFILMDKT, K2KSB2XTLS and BFOMDKT?
I would have done that already except K2BCOMPKT says it *requires*
FWK2MCIO...which nearly doubles the cost.

Furthermore, I'll probably finish the Rev A control board today....I
wonder if a Rev A control board plays nice with Rev B RF and/or Front Panel?

  73 all de Maggie K3XS

--
-----/___.   _)Margaret Stephanie Leber CCP, SCJP/"The art of progress /
----/(, /|  /| http://voicenet.com/~maggie SCWCD/ is to preserve order/
---/   / | / |  _   _   _    `  _  AOPA 925383/ amid change and to  /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_      K3XS / preserve change amid/
-/ (_/   '        .-/ .-/        ARRL 39280 /order."-A.N.Whitehead/
/________________(_/_(_/_______AMSAT 32844_/<[hidden email]>/

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[Ron D'Eau Claire-2]

Ha! I avoided getting into the mods, Margaret!

I'd build the basic K2 as you see in the book, see that it is working
properly, then add the mods one at a time while checking operation in
between. That way, if you do stumble, you'll see where and what you did much
more easily.

The filter flattening mod is a simple one that you'll love it especially if
you try to listen to SSB. There's a real 'tilt' to the original second
filter bandpass in the pre S/N 3000 design. That's the filter at the output
of the I.F. amp that is there just to clean up excess wideband noise, so
it's involved whether you have the SSB adapter or not.

I would also recommend the AF gain control mod and the PLL and BFO
oscillator stability mods for a CW op.

The new crystals are a good idea if you are including the SSB adapter.

The oscillator stability mods really show up mostly on the higher-frequency
bands above 20 meters. On the lower bands, the drift in these oscillators
tend to cancel,  but on the bands above 20 they add due to the way the
mixing scheme works. That can produce excessive drift on the higher bands.

I'd not hesitate to operate the K2 without the mods in any but the most
demanding service such as PSK31 and then only be really concerned on the
higher bands.

The firmware upgrades have greatly improved the frequency readout accuracy
of the K2 and so having more stable oscillators helps you make use of that
improvement.

If you're going to add the KPA100 for QRO operation, it's nice to install
the keying shaping mod as well, although the K2 needs no apologies without
it. And if you do that, you don't need the KIO2. The KIO2 is part of the
KPA100 100 watt upgrade option.

But first, your K2 as it came will work FB. Use it and decide what you want
it to do for you, then choose the  additions and mods that fit!

So far, retirement isn't a visible stage of life for me either but I'm
having fun in the meantime. Bob Hope laid out the future as far as I can
see: when we reach 70 he says that us guys still chase women, but we'll only
chase 'em downhill. Then by age 80 he warns that even our birthday suits
will need ironing.

Ron AC7AC


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[Vic K2VCO]

Ron D'Eau Claire wrote:

> The oscillator stability mods really show up mostly on the higher-frequency
> bands above 20 meters. On the lower bands, the drift in these oscillators
> tend to cancel,  but on the bands above 20 they add due to the way the
> mixing scheme works. That can produce excessive drift on the higher bands.
>
> I'd not hesitate to operate the K2 without the mods in any but the most
> demanding service such as PSK31 and then only be really concerned on the
> higher bands.

Ron is correct, but I'd like to add that the VFO stability mod should be
considered a must if you are planning to add a KPA100.  The extra heat will
cause very noticeable drift.

--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco

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[Margaret Leber]

Ron D'Eau Claire wrote:
> Ha! I avoided getting into the mods, Margaret!
>
> I'd build the basic K2 as you see in the book, see that it is working
>  properly, then add the mods one at a time while checking operation
> in between. That way, if you do stumble, you'll see where and what
> you did much more easily.

Point well-taken.

Sounds like a programmer thinking. Fortunately programming is not done
on double-sided PC boards. Anymore.

I'm still delighted that I've finished the N0SS noise source and the K2
control board and neither looks like the kind of train wreck some of my
earlier ventures into kitbuilding have. Of course, those traumas were
*long* ago and far away; I'm more experienced and have vastly better
tools now. I think temperature-control on the soldering iron is a big
factor. So are a Panavise and lighted magnifier...given my current
vision the latter is just about a necessity.

> I would also recommend the AF gain control mod and the PLL and BFO
> oscillator stability mods for a CW op... The new crystals are a good
> idea if you are including the SSB adapter.

Yes...definately doing the AF gain mod. and I do have the SSB adapter
in-hand. Interesting thing is, I suspect I'm likely to play more with CW
once I have a K2...I hardly ever do that now.

> If you're going to add the KPA100 for QRO operation, it's nice to
> install the keying shaping mod as well, although the K2 needs no
> apologies without it. And if you do that, you don't need the KIO2.
> The KIO2 is part of the KPA100 100 watt upgrade option.

(Vic Rosenthal wrote:)
> Ron is correct, but I'd like to add that the VFO stability mod should
> be considered a must if you are planning to add a KPA100.  The extra
> heat will cause very noticeable drift.

I doubt I'll do the KPA100; I already have a Yaesu FT-847.
But ya never know.

> But first, your K2 as it came will work FB. Use it and decide what
> you want it to do for you, then choose the  additions and mods that
> fit!

Yes, that's a good point. I suspect having a K2 will change the kind of
operating I do.

> So far, retirement isn't a visible stage of life for me either but
> I'm having fun in the meantime. Bob Hope laid out the future as far
> as I can see: when we reach 70 he says that us guys still chase
> women, but we'll only chase 'em downhill.

Well, I'm just past 50 and already I'll only run downhill anyway. And
even that way not very fast. :-)

  73 de Maggie

--
-----/___.   _)Margaret Stephanie Leber CCP, SCJP/"The art of progress /
----/(, /|  /| http://voicenet.com/~maggie SCWCD/ is to preserve order/
---/   / | / |  _   _   _    `  _  AOPA 925383/ amid change and to  /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_      K3XS / preserve change amid/
-/ (_/   '        .-/ .-/        ARRL 39280 /order."-A.N.Whitehead/
/________________(_/_(_/_______AMSAT 32844_/<[hidden email]>/

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[Margaret Leber]

Wayne wrote:

> Where are all these mods?

At the Elecraft website.

For those of you who tuned in late, I have a fairly early S/N (1641) K2
kit that's been languishing in my closet for about four years. I've just
resumed work on it, and the K2 design has evolved a bit over that period
of time.

I beleive all of the mods that are being discussed are already
incorporated in modern K2s as shipped; this discussion is only about
what it makes sense to do with my antique kit that's a-building now.

  73 de Maggie K3XS

--
-----/___.   _)Margaret Stephanie Leber CCP, SCJP/"The art of progress /
----/(, /|  /| http://voicenet.com/~maggie SCWCD/ is to preserve order/
---/   / | / |  _   _   _    `  _  AOPA 925383/ amid change and to  /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_      K3XS / preserve change amid/
-/ (_/   '        .-/ .-/        ARRL 39280 /order."-A.N.Whitehead/
/________________(_/_(_/_______AMSAT 32844_/<[hidden email]>/

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